Gravimetric feeder

ABSTRACT

Apparatus for feeding particulate solid material having a main frame, an enclosed volumetric prefeeder mounted on the main frame, a motor for driving the prefeeder, the prefeeder having an enclosed dispensing outlet, a downspout connected to the dispensing outlet in fixedly sealed relationship, an enclosed auger type conveyor, a sealing member for flexibly connecting in sealed relationship the downspout to the conveyor, a driving member for driving the auger in the conveyor, a connecting member for flexibly connecting the conveyor in sealed relationship to the discharge conduit.

United States Patent 1 Ricciardi Apr. 16, 1974 GRAVIMETRIC FEEDER [76] Inventor: Ronald J. Ricciardl, 193 McArthur Ave., Garfield, NJ. 07026 [22] Filed: July 25, 1972 [21] Appl. No.: 274,848

[52] U.S. Cl. .L. 222/56, 222/413 [51] Int. Cl B67d 5/08 [58] Field of Search 222/56, 238, 413

[56] References Cited UNITED STATES PATENTS 3,494,507 2/1970 Ricciardi 222/56 A 3,253,745 5/1966 Skelton 222/56 2,743,850 5/1956 Hamilton 222/238 2,381,505 8/1945 Lindholm 222/56 3,091,368 5/1963 Harley et a1... 2,276,382 3/1942 Francis 222/56 Primary Examiner-Robert B. Reeves Assistant Examiner-David A. Scherbel Attorney, Agent, or FirmFitzpatrick, Cella, Harper & Scinto [5 7] ABSTRACT Apparatus for feeding particulate solid material having a main frame, an enclosed volumetric prefeeder mounted on the main frame, a motor for driving the prefeeder, the prefeeder having an enclosed dispensing outlet, a downspout connected to the dispensing outlet in fixedly sealed relationship, an enclosed auger type conveyor, a sealing member for flexibly connecting in sealed relationship the downspout to the conveyor, a driving member for driving the auger in the conveyor, a connecting member for flexibly connecting the conveyor in sealed relationship to the discharge conduit.

3 Claims, 4 Drawing Figures I PATENTED 3.804.298

SHEET 1 nr 2 GRAVIMETRIC FEEDER This invention relates to an apparatus for meteringand feedingparticulate solid material. It is particularly adapted, among other possible uses, for accurately metering and feeding material that is free-flowing, sluggish or pressure sensitive and which ranges from amorphous powders to flakes, pellets, chunks and even fibers.

Particular apparatus of the class described is disclosed in my own US; Pat. No. 3,494,507, dated Feb. I0, 1970, which has experienced wide commercial acceptance. The present invention concerns improvements uponthe features of such apparatus, particularly as applied to certain types of applications wherein dust confinement is necessary or desirable; and wherein material is handled which must be maintained free of contamination. It. is, therefore, the purpose of this invention to provide a novel combination of features combined in such a way as to provide the foregoing desired operative effects.

In order to accomplish the desired results, my invention contemplates the provision of a new-andimproved apparatus for feeding particulate solid material characterized by a mainframe, and an enclosed volumetric type prefeeder having enclosed discharge means feeding into enclosed inlet means of an encapsulated auger type conveyor which, in turn, has enclosed outlet means. Weighing means are provided for the encapsulated auger, and control. valve means are provided which are responsive to the weighing means and serve to control the volumetric outflow of the. prefeeder. There has been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present conbribution to the art may be better appreciated. there are, of course, additional features of the invention that will be described more fully hereinafter. Those skilled in the art will appreciate. that the conception on which this disclosureis based may readily be utilized as the basis for the'designing. of other structures for carrying out the purposes of the invention. It is important, therefore, that this disclosure be regarded. as including such equivalent constructions as do not depart from the spirit and scope of the invention.

One embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawings forming a part of the specification, wherein:

FIG. 1 is a schematic side elevation showing apparatus for feeding particulate solid material constructed according to the concepts of my invention;

FIG. 2 is an enlarged, side elevation view, partly in medial section, showing details of the encapsulated auger;

FIG. 3 is an enlarged, plan view showing the feeding apparatus; and

FIG. 4 is an enlarged end view of the apparatus of FIGS. 1-3.

In the illustrated embodiment of the invention, the feeding apparatus comprises a main frame 10, FIG. 2, upon which is mounted a volumetric auger type prefeeder 12, having an upper inlet 14, FIG. I, for receiving material to be processed and a lower enclosed dispensing outlet 16. A particularly suitable type of volu-' metric profeeder for this purpose is described in detail in my US. Pat. No. 3,186,602, issued June I, I965.

As best seen in FIG. 2, the prefeeder 12 employs an auger l8 driven by a motor 20, FIG. 1, for propelling the material through the outlet 16 into a downspout 22, as indicated by arrow 24, FIG. 2. The dispensing outlet and thedownspout are mounted in fixedly sealed relationship with respect to each other. The downspout leads to the inlet of an enclosed auger type conveyor 26, which incorporates an auger 28 having a drive shaft 30 driven at substantially constant speed by a motor 32, FIG. 3, by means of a chain and pulley system 34. The auger 28 serves to move the material through a conveyor cylinder 36 to a discharge outlet 38 where it passes into a discharge conduit 40, as indicated by arrow 42, FIG. 2. The conduit 40 is mounted on the main frame 10, as at 43.

The conveyor 26 is mounted in such a manner that the entire assembly and its contents can be sensed" or weighed by a force sensing load cell, such as a low voltage differential transformer LVDT 44. As best seen in FIGS. 3 and 4, the conveyor 26 is carried by a conveyor support frame 46, which is fixedly connected thereto, as at 48, FIG. 4. Also, the motor 32 is fixedly connected to the conveyor support frame 36, as at 50, FIG. 3. Reverting to FIG. 2, it will be seen that the movable conveyor cylinder 36 is flexibly connected in sealed relationship to the fixed downspout 22, as by means of a downspout sleeve 52. In addition, the movable cylinder 36 is flexibly connected in sealed relationship to the fixed discharge conduit 40, by means ofa sleeve clamping assembly 54. Accordingly, it will be appreciated that the material being processed passes through a completely closed system from inlet to outlet, thereby providing the advantages set forth hereinbefore.

As best seen in FIG. 2, the conveyor support frame 46 includes vertical stabilizer bars 56, which engage a balanced beam assembly 58 that, in turn, actuates the low voltage differential transformer 44. This device translates mechanical displacement into an electrical signal, which can be used for visually monitoring of the weight variation of the material in process by means of an indicator 60, FIG. I, provided for the purpose. In addition, the same signal is transmitted to a controller 62, which also receivesa signal from a set point signal means 64, so that the setting of the desired feed rate by the operator is compared to the signal received from the low voltage differential transformer( LVDT). Responsive to the comparative signals, the controller 62 sends a signal to the motor 20 which drives the volumetric feeder 12 to control the rate of passage of the material therethrough. In addition, a total feed rate indicator 66 may be employed which receives a signal from the LVDT 44 and is adapted to indicate the total feed weight over a prescribed period of time. Accordingly, it will be appreciated that this apparatus is capable of feeding particulate solid material, either continuously, or in a batch-type of operation, with a high degree of accuracy.

As seen in FIG. 2, the discharge conduit 40 is provided with an auger access door 68 to facilitate assembly and maintenance and, in addition, it is provided with a hinged inspection door 70 for purposes of visually inspecting the system.

It will thus be seen that the present invention does indeed provide an improved feeding apparatus capable of handling a wide variety of materials having different physical and chemical characteristics, which is superior in providing a dust-proof system and handling material which must be maintained free of contamination, and which is reliable and efficient as compared to prior art such apparatus.

Although a particular embodiment of the invention is herein disclosed for purposes of explanation, various modifications thereof, after study of the specification, will be apparent to those skilled in the art to which the invention pertains.

What is claimed and desired to be secured by Letters Patent is:

1. Apparatus for feeding particulate solid material comprising a main frame, an enclosed volumetric prefeeder mounted on said main frame, means for driving said prefeeder, said prefeeder having an enclosed dispensing outlet, a downspout connected to said dispensing outlet in fixedly sealed relationship, an enclosed auger conveyor, means for flexibly connecting said conveyor in sealed relationship to said downspout, means for driving said auger, said conveyor having a dispensing outlet, a discharge conduit, means for flexibly connecting said dispensing outlet of said conveyor in sealed relationship to said discharge conduit and continuous weighing means for said enclosed auger conveyor, and wherein said means for driving said enclosed volumetric prefeeder is responsive to said weighing means.

2. Apparatus for feeding particulate solid material according to claim 1, wherein said means for flexibly connecting said conveyor in sealed relationship to include a downspout sleeve, and said means for flexibly connecting said dispensing outlet of said conveyor in sealed relationship to said discharge conduit includes a sleeve clamping assembly.

3. Apparatus for feeding particulate solid material comprising a main frame, an enclosed volumetric auger prefeeder mounted on said main frame, motor means for driving said prefeeder, said prefeeder having an enclosed dispensing outlet, a downspout connected to said dispensing outlet in a fixedly sealed relationship with respect thereto, a conveyor support frame, an enclosed auger conveyor mounted on said conveyor support frame, a downspout sleeve for flexibly connecting in sealed relationship said conveyor to said downspout, means for driving the auger in said conveyor at substantially constant speed, said conveyor having a dispensing outlet, a discharge conduit fixedly mounted on said main frame, a sleeve clamping assembly for flexibly -connecting said discharge conduit in sealed relationsaid prefeeder. 

1. Apparatus for feeding particulate solid material comprising a main frame, an enclosed volumetric prefeeder mounted on said main frame, means for driving said prefeeder, said prefeeder having an enclosed dispensing outlet, a downspout connected to said dispensing outlet in fixedly sealed relationship, an enclosed auger conveyor, means for flexibly connecting said conveyor in sealed relationship to said downspout, means for driving said auger, said conveyor having a dispensing outlet, a discharge conduit, means for flexibly connecting said dispensing outlet of said conveyor in sealed relationship to said discharge conduit and continuous weighing means for said enclosed auger conveyor, and wherein said means for driving said enclosed volumetric prefeeder is responsive to said weighing means.
 2. Apparatus for feeding particulate solid material according to claim 1, wherein said means for flexibly connecting said conveyor in sealed relationship to include a downspout sleeve, and said means for flexibly connecting said dispensing outlet of said conveyor in sealed relationship to said discharge conduit includes a sleeve clamping assembly.
 3. Apparatus for feeding particulate solid material comprising a main frame, an enclosed volumetric auger prefeeder mounted on said main frame, motor means for driving said prefeeder, said prefeeder having an enclosed dispensing outlet, a downspout connected to said dispensing outlet in a fixedly sealed relationship with respect thereto, a conveyor support frame, an enclosed auger conveyor mounted on said conveyor support frame, a downspout sleeve for flexibly connecting in sealed relationship said conveyor to said downspout, means for driving the auger in said conveyor at substantially constant speed, said conveyor having a dispensing outlet, a discharge conduit fixedly mounted on said main frame, a sleeve clamping assembly for flexibly connecting said discharge conduit in sealed relationship to said dispensing outlet of said conveyor, a balance beam assembly, said conveyor support frame being mounted on said balance beam assembly, a low voltage differential transformer actuated by said balance beam assembly to convert mechanical movement of said balance beam assembly into electrical signals, a controller for receiving said electrical signals, set point signal means adjustable by an operator to send a signal to said controller corresponding to the desired feed rate, said controller being adapted to compare signals received and to control said motor means for driving said prefeeder. 